This invention relates to spinning units of an open end spinning machine, and more particularly to mounting of fiber supply channel defining means in such spinning units.
Each spinning unit of an open end spinning machine generally includes a spinning rotor mounted for rotation with an inner frustoconical surface defining a maximum inner diameter portion at which individual fibers are formed into a yarn, and stationary means having a body defining a housing within which a carding roller is mounted for rotation to open a sliver into the afore-mentioned individual fibers. The body of the stationary means includes a portion, which slightly enters the spinning rotor through the opened end thereof and defines a fiber supply channel or passage to allow the individual fibers to be supplied from the carding roller into the spinning rotor therethrough. Thus, the supply channel has opposite mouths respectively opening towards the carding roller and the spinning rotor. The mouth opening towards the carding roller is defined at least in part by an edge portion, of which the sharp edged part is generally referred to as a fiber separating edge.
In such spinning units, since the fibers which have been individually opened by the carding roller are separated from the carding roller by the fiber separating edge, i.e., the fibers pass across the fiber separating edge and through the supply channel, the fiber separating edge will always be subject to wear during operation of the spinning machine. Therefore, after a certain period of operation, the fiber separating edge will wear away, resulting in a poor fiber separating function.
Furthermore, the fiber supply channel generally converges towards the mouth of the spinning rotor side so as to limit radially outward movement of the individual fibers in the supply channel, thereby to allow the fibers to be supplied onto the inner frustoconical surface of the spinning rotor in a most favorable condition. However, such a configuration of the supply channel will cause undesirable matter, such as oil, lubricant and cotton wax, contained in the fibers to adhere to the supply channel surface due to an increasing contact of the fibers with the supply channel surface. After a certain period of spinning operation, the quantity of such matter will become considerable, which may interfere with the movement of the separate fibers through the fiber supply channel.
In order to avoid the above disadvantages, it is therefore necessary to renew the portion with the fiber separating edge and periodically to clean off the adhering matter.